Method of making a friction disc

Abstract

The invention relates to friction discs of the progressive engagement type, especially for clutches of heavy automobile vehicles, the disc comprising two annular friction linings extending respectively on both sides of and in contact with a cut-out corrugated support, each lining being fixed individually by continuous glueing zones on this support, along parts of the corrugations of the support which are in contact with the lining. The surface area of the glueing zones should be between 5 and 35%, and preferably about 10% of the surface area of the lining. In a modification, each lining is fixed on the support, not only by the glueing zones but also by at least one rivet per zone arranged at right angles to each glueing zone. The riveting operation is preferably carried out after glueing and before the adhesive is polymerized or set.

What I claim is: 
     
       1. A method of manufacture of a friction disc of the progressive engagement type, said method comprising the steps of: first manufacturing three elements constituted by two flat annular friction linings and a cut-out and corrugated support; coating with adhesive at least a part of these elements at least over the regions corresponding to glueing zones which zones include the parts of the corrugations of the support which are in contact with said linings; and carrying out a riveting operaton with rivets in said glueing zones before setting of the adhesive, whereby said rivets play the part of a joint-clamping means during the setting of said adhesive. 
     
     
       2. A method as claimed in claim 1, in which the inner faces of said friction linings are coated with adhesive before riveting. 
     
     
       3. A method as claimed in claim 1, in which regions of at least a part of the inner faces of said friction linings which correspond exactly to said glueing zones are coated with adhesive before riveting. 
     
     
       4. A method as claimed in claim 1, in which regions of at least a part of the inner faces of said friction linings which extend beyond said glueing zones are coated with adhesive before riveting. 
     
     
       5. A method as claimed in claim 4, in which the whole of the internal faces of said friction linings is coated with adhesive before riveting.